Inactivation of genes and impairs its pathogenicity .

orchestrates the development of a biofilm that causes dental caries in the presence of dietary sucrose, and, in the bloodstream, can cause systemic infections. The development of a cariogenic biofilm is dependent on the formation of an extracellular matrix rich in exopolysaccharides, which contains extracellular DNA (eDNA) and lipoteichoic acids (LTAs). While the exopolysaccharides are virulence markers, the involvement of genes linked to eDNA and LTAs metabolism in the pathogenicity of remains unclear. In this study, a parental strain UA159 and derivative strains carrying single gene deletions were used to investigate the role of eDNA (Δ and Δ), LTA (Δ and Δ), and insoluble exopolysaccharides (Δ) in virulence in a rodent model of dental caries (rats) and a systemic infection model ( larvae). Fewer carious lesions were observed on smooth and sulcal surfaces of enamel and dentin of the rats infected with ∆, ∆, and Δ (vs. the parental strain). Moreover, strains carrying gene deletions prevented the killing of larvae (vs. the parental strain). Altogether, these findings indicate that inactivation of and impaired cariogenicity and virulence .